Regarding my parenthetical comment: the server can ignore input that was not received in time, block while waiting for input, or try to "rewind" the world. The

Regarding my parenthetical comment: the server can ignore input that was not received in time, block while waiting for input, or try to "rewind" the world. The first is lossy, the second leads to the same hiccups as reliable transmission protocols (although the effect may be smaller), and the third leads to "paradox" (and lots of complexity). There are no really good solutions here. I agree that such codes are interesting, though - I really should know more coding theory...